May, 1910.] The Ohio Powdery Mildews. 173 



Microsphaera alni vaccinii (Schw.) Salm. Perithecia scat- 

 tered, 7U-145 /( in diameter; cells 10-20 ;.l; appendages 4-22, 

 23^-8 times diameter of perithecium, colorless, or darker at 

 base, nonseptate, apex 2-4 times dichotomously branched, ulti- 

 mate bran chlets recurved; asci 2-16, 45 x 28-72 x 38 n\ spores 

 4-6, IS X 10-22 X 13 /^. 



Host plants in Ohio Herbarium: Vaccinium vacillans, Portage Co., 

 Lake Co., E. Claassen, Vaccinium corymbosum, Portage Co., E. Claassen; 

 Catalpa bignonoides, Columbvis, C. M. Weed, Oberlin, F. D. Kelsey, 

 Toledo, F. D. Kelsey. 



Microsphaera russellii Clinton. Perithecia scattered, 70-118 

 H in diameter; cells 6-14 /<; appendages 5-14, 3-7 times diameter 

 of perithecium, septate, colored nearly to apex, 2-4 times 

 dichotomously branched, branches irregular and lax, tips not 

 recurved, primary branches long; asci 4-9, short-stalked, 42 x 24— 

 56 x 32 /x; spores 4, 18 x 10-22 x 12 /«. Appendages not branched 

 until fully mature. 



Host plants in Ohio Herbarium: Oxalis stricta, Hamilton Co., W. H. 

 Aiken, Columbus, W. A. Kellerman. 



Otherwise reported in Ohio: Oxalis recurva, E. M. Wilcox. 



Microsphaera diffusa C. & P. Perithecia 55-126 //. in diam- 

 eter; cells 10-20 jx; appendages 4-30, 1-1 2-7 times diameter of 

 perithecium, sometimes septate in lower half, colorless, thicker 

 walled toward base, apex 3-5 times irregularly dichotomously 

 branched, tips swollen and not recurved; asci 4—9, 48 x 28— 

 60 X 30 IX, with very short stalk ; spores 4, 18 x 9-22 x 11 11. 



Host plants in Ohio Herbarium: Meibomia canescens, Meibomia 

 dillenii, Cuyahoga Co., E. Claassen; Desmodium sp., Franklin Co., F. L. 

 Stevens; Desmodium nudiflorum, Columbus, C. M. Weed. 



Otherwise reported in Ohio; Desmodium canescens, Columbus, C. M. 

 Weed, F. Detmers, A. D. Selby. 



Microsphaera grossulariae (Wallr.) Lev. Perithecia 65-130 fx 

 in diameter; cells 14-20 fx; appendages 5-22, 1-1 M times diam- 

 eter of perithecium, colorless, nonseptate, thicker walled toward 

 base, apex 4-5 times dichotomously branched, branches close 

 and regular, and ultimate branches long, giving a digitate 

 appearance ; asci 4-10, short stalked, 40 x 28-62 x 38 /<; spores 4-6, 

 20 X 12-28 X 16 //.. 



Host plants in Ohio Herbarium: Sambucus canadensis, Columbus, 

 W. A. Kellerman, Sugar Grove, W. A. Kellerman. 



Phyllactinia Lev. 



Phyllactinia corylea (Pers.) Karst. Perithecia 150-275 ix in 

 diameter; cells 10 to 15 tx; appendages 8-12, equatorial, length 

 •% to 4 times diameter of perithecium, sharp-pointed, with bul- 

 bous base; asci 5-20, stalked, 30 x 90 /«; spores 2, 14 x 18 ix. 



